Time-limit controlling device for electric switches.



G. A. BURNHAM.

TIME LIMIT CONTROLLING DEVICE FOR ELECTRIC SWITCHES.

APPLlcATloN FILED 050.143.1912.

Z1/aven Zar TIME LIMIT CONTROLLING DEVICE FOR ELECTRIC SWITCHES.

APPLICATION FILED DEc.23. I9I2.

1,237,240u Patented Aug. 14,1917;

2 SHEETS- SHEET 2.

UNITED sTATEs PATENT oE-ErcE.

GEORGE A. BURNHAM, OF SA'UGUS, MASSACHUSETTS, ASSIGNOR TO SEARS B. CONDIT, JR., 0F BROOKLINE, MASSACHUSETTS.

TIME-LIMIT CONTROLLING DEVICE FOR ELECTRIC SWITCHES. p

Specication of Letters Patent. .Patented Aug. 14, 1917,.

Application led December 23, 1912. Serial No. 738,161.

To all whom t may concern.'

B e it known that I, GEoRGE A. BURNHAM, a. citizen of the United States, residing at Saugus, in the county of Essex and ,State of Massachusetts, yhave invented an Improvement in Time-Limit Controlling Devices for Electric Switches, of which the following is a speciiication.-

This invention relates to selective time-limit controlling devices for electric-switches, and is intended as an improvement upon the selective time-limit controlling-device of Patent #1,041,716, dated October 15, 1912. In said patent an electric-motor, responsive to an overload, is employed for moving the switch-operating device into engagement withits actuator and subsequently for driving said actuator to cause the switch ope-rating-device'to operate the switch. There are movable means connected with the motor for controlling the engagement of the switch-operating device with its actuator, whereby the switch-operating device is held disengaged from its actuator on an overload of lesser value than that which is designed to move it, permitting engagement of said operating-device with its actuator to be effected by an overload of at least a given value or in excess of such value. There are also means connected with the motor for controlling the starting thereof, whereby it willbe held at rest on an overload of a lesser value than that which is designed to start and operate. it. The movable means for controlling the engagement of the switchoperating device with its actuator is shown in said patent as a movable part of the fieldframe, or a movable part which is arranged in the magnetic-field of the motor, said movable part adapted to .be moved in one direction by the attractive influence of saidl field to cause the switch operating-device to engage its actuator and a spring is connected with said movable part for moving it in the other direction, said spring being adjusted to hold said part against the attractive influence of the magnetic-field upon an overload of lesser value than that which is designed to overcome its force. The means which is connected with the motor for controlling the starting thereof, consists of a brake for the armature, and said brake is connected with said movable means, whereby it is held in engagement with the armature upon an overload of lesser value than that vris` responsive to .an overload current, and

furthermore is or may be adjustable to start and operate the motor on-overloads of different values or in excess of such values.

Figure- 1 is a'side elevation of a time-limit controlling-device embodying this invention.

Fig. 2 is an end view of the same.

Fig. 3 is a diagram of the circuits.

y The novel features embodying my present invention are here' illustrated in connection with' a time-limit controlling-device such as shown in said patent, but they may be arranged in connection with other forms of time-limit controlling-devices involving the employment of a motor of any form in which motive power is derived from electric currents by means of. electro-magnetic action.

Referring to the drawings, the switchoperating-device comprising a yoke or arm 40, with a cross-piece 41 for .engagement with a circuit-closing member 27, a shaft 42 upon which said arm is loosely mounted, worm-wheel 43 arranged on said shaft, and screw 44 for detachably connecting said arm with the worm-wheel; a movable part or member 51 of the field-frame of an electricmotor, -pivoted at 52, and bearing said switch-operating device; a worm 49 into and out of engagement with which said worm-wheel is movable, which is arranged on the shaft of the armature of said motor, are all as shown in the patent referred to.

Herein the field-coils 60, which are arranged on the eld-frame, or the equivalent exciting-coils of the motor, have connected with them numerous branch wires 61, which lead to a corresponding number of stationary switch-plates 62, arranged adjacent a switch-plate 63, which is common to all said switch-plates 62, and sockets are provided between said switch-plates 62, and the switch-plate 63, to receive 'a switch-plug 64, or equivalent conducting member, thereby to motor.

electrically connect the switch-plate 63 with any one ofthe switch-plates 62 for the purpose of including more or less of the exciting-coils in the circuit. A transformer-circuit 70, or equivalent circuit arranged to be ai'ected by the overload, is connected with the switch-plate v63 and withv the excitingcoils, as represented in the diagram Fig. 3, or otherwise, whereby the results herein described may be attained. l

By means of the electrical connections and circuits here shown the magnetic-field of the motor will be variable, according to the portion or number' of exciting-coils included in the transformer-circuit, and the movable part or member 51 of the fieldframe will be caused to respond to any amperage of current for which the device may be set, thus widely increasing the range of adjustment, as contrasted with the employment of a spring, as shown in the patent referred to. As the movable part or member 51 responds the switch .operating-device will be moved into engagement with its actuator, but it will be noted that such part or member will not be moved until the magnetic-ield is at least of a given stren h, due to an overload of at least a given-,va ue.

The .electric motor here shown is off/the repulsion type adapted for operation when its armature is short circuited and herein the armature winding of the motor is ar-` ranged in a circuit 85, which is adapted tc be opened and closed by a movable switchmember 86, engaging stationary Y switchmembers which are connected with-the circuit 85, for the purpose of starting the In order lthat said movable switchmember may 'bejresponsive to an overload it is here shown as connected with the movable part 51 of the eld-frame, or other movable means which may be employed in. lieu thereof, so that when said. part or equivalent movable means is moved in response to an v'overload of a given value or amperage, or of a greater value or ampera e, said switch-member will be moved and t e circuit V85 of thearmature closed, thereby startin the motor. Hence the starting 'of the mo orand also the operation thereof is controlled by an overload, and furthermore by an overload of at least a given value which may be predetermined, and adjustment made to provide for it. This means of starting the motor is of advantage even though a spring is connected with the movable means for controlling its movement, as in the patent referred to.

I desire to include particularly within the spirit and scope of my invention the adjust- Vable means herein set forth for controlling the operation of the motor on overloads oi different predetermined values or in excess of such values, as a motor so controlled is of advantage in connection with a time-limit' point Leanne lated closedcircuit which is so arranged inthe magnetic-circuit that a current of a' phase relation different from that of the ield-coils may traverse the closed circuit andcause said part 5l to remain inv attracted position. In said patent the operating-device for the switch is designed to be moved through a definite interval of space to operate the switch, according to the setting, and for the accomplishment of this result the worm-wheel is provided with a series of holes to receive a screw connected 'withj the yoke or frame, and the pin 46 is arranged on the worm-wheel which enga es the stop on the frame for determining t e normalzposition or starting point. For ordinary purposes this adjustment is suiicient but in some instances a finer adjustment is required, and to rovide for a finer adjustment in a `simple manner an adjustingscrew l95 is arrangedin lthe frame, as a stop, for engagement with the pin 46, thereby to determine the normal positio'n or starting b of the movableswitch-opeating memer. Y i

lI Ydo not desire to limit my invention to the particularvconstruction here shown, as it is obvious that the same may be` modified in many respects yet enable the results here shown to be attained, which come within the spirit and scope of this invention.

I claim 1. In a time-limit' switch controller, a switch-closing member arranged to close-a switch when actuated a predetermined distance, having an engaging portion adapted -to engage the rotary portion of a motor a switch adapted to close an electric circuit erived from. the circuit to be controlled to actuate the motor, a rotary electric motor having a portion adapted to be moved by electromagnetic attraction of its parts on the occurrence of a predetermined overload on the circuit to be controlled and cause said switch closing mechanism to be connected with the rotating portion of said motor and also close the switch which controls the actuation of the motor. 4

2. A time-limit device for electricf switches consisting of a switch-operating device, an actuator therefor into and out of engagement with which said operating device 1s movable, an electric-motor for controlling said actuator, which is responsive to an overload current, and means associated with said motor, and responsive to an over- 'e said controlling-switch and start the motor,

load current, which is arranged to start said motor and also to move said operating-device into engagement with its actuator upon an overload of at least a` given value, substantially as described.

3. A time-limit device for electricswitches Y"consisting of a switch-operatingdevice, an actuator therefor into and out of 4engagement with which said operating-device is movable, an electric-motor for controllingk said actuator which '1s responsive to an overloadcurrent, means associated with said motor and responsive lto an overload current, which is arrangedl to `start said motor and also topmove said operating-device into engagement with its actuator'upon an overload of at least a given value, and means arranged to vary the value ofV the overload to which said starting and moving-means is responsive, substantially as described.

4. A 'time-limit device :for electricswitches consisting of anl` operating-device requiring a prolonged period of time to operate the iswitch, an actuator therefor, anV

electric-motor for controlling said actuator which is responsive to an overload current,

a controlling-switch for the circuit of the* armature of said motor, and means responsive toan overload current arranged to control the engagement of said operating-device with its actuator and also to operatel said controlling-switch to close its circuit upon an overload of at least a given value, and which permits of disengagement of said operating-device'from its actuator and the return of said switch to normal when the overload ceases, substantially as described.

5. A time-limit device for electricswitches consisting of an operating-device requiring a prolonged period of time to operate the switch, an. actuator therefor, an

velectric-motor for driving said actuator which is responsive to an overload current, a controlling-switch for the circuit of the armature of said motor, and movable means y bearing the vmovable member of said controlling-switch, which is arranged in the magnetic-field 'of the motor and adapted to be moved by the attractive influence of said v field to close said controlling-switch and c erate thev switch, an actuator therefor, an electric-motor for driving said actuator thereby start the motor, vsubstantially as describe 6.-- A time-'limit device for electric switches consisting of an operating-device requiringA a prolonged period of time to opwhich is responsive-to an overload current, a. controlling-switch for Athe circuit of vthe armature 'ofsaidmotor, amovable part of the field-'frame of said motor bearing the movable member ofI said controlling-switch,

'said movable partadapted to be moved by the attractive influence of the field to close of said controlling-switch and also controlling the engagement of said operating-device with its actuator, said movable part adapted to be moved .by the attractive iniuence of the field upon the occurrence of an, overload to close said controlling-switch and start the motor and also move said 0perating-device into engagement with its actuator, substantially as described.

8. A time limit device for -electricswitches consisting of an operating-device requiring a prolonged period of time to operate the switch,-anN actuator therefor, into and out of engagement with which said operating-device is movable, an electrlc-motor .for driving said actuator which is responsive to an overload current, a controllingswitch for the circuit ofthe armature of said motor, a movable part of the field-frame of said motor bearing the movable member of said controlling-switch, and also controlling the engagement of said operatingdevice with its actuator, said movable part adapt- ,ed to be moved by the attractive iniuence of the field upon the occurrence of an overload to close said controlling-switch and start the motor and also move said operating-device into engagement with its actuator, and means arranged to vary the value of the overload to which said movable part ofY the field-frame is responsive, substantially as described.

9. A time-limit. device .for electricswitches consisting of a switch-operating device, an actuator therefor, an electric-motor :Eorccontrolling said actuator, the excitingcoils of which are included in-a circuit responsive to an overload, and the armature of` which has its windings arranged in a circuit inductively related to theaforesaid circuit, and means controlled by saidlexcitinlg-coils ,and responsive to kan overload of, atI east a given value to closethe circuit of said armature, thereby to start saidmotor only upon the occurrence of an overload of at "least 1a given value, substantially as described.

10. A time-limit devicer for electricswitches consisting of a switch-operating de-, vice, an actuator therefor, into and out of engagement with which said operating-device is movable, anelectric-motor for controlling said actuator, the exciting-coils of which are included in a circuit responsive to an overload current, and the armature of which has its windings arranged 1n a circuit inductively related to the aforesaid circuit l 5 and means controlled by said exciting-coils and responsive to an overload of at least a given value, to close the circuit of said armature and to move the operating-device into engagement with its actuator, thereby to start the motor and also effect engagement for the operating-device with its actuator only upon the occurrence of an overload of at least a given value, substantially as described.

11. A time-limit device -for electric- 'switches consisting of a switch-operating device, an actuator therefor, into and out of engagement with which said operating-device is movable, an electric-motor for controlling said actuator, the exciting-coils of which are included in a circuit responsive to an overload current, and the armature of which has its windings arranged .in a circuit in- `ductively related to the aforesaid circuit, and means controlled by said exciting-coils and responsive to an overload of at least a" given value, to close the circuit of said armature and to move the operating-device into engagement with its actuator, thereby to for the operating-device with its actuator only upon the occurrence of an overload of at least a given value, and means arranged to vary the value of the overload to which said controlling-means is responsive, substantially as described.

12. A, time-limit device for electric switches consisting of an operating-device requiring a prolonged period of time to operate the switch, an actuator therefor, and an electric motor for said actuator, the Heldmagnets of which are included in a circuit responsive to an overload, and movable means associated with said motor and adapted to control the starting thereof by closing the circuit of the armature when the Held-magnets have become magnetized by an Ioverload of at least a given current value, substantially as described.

13. In a time-limit switch controllerLan electric motor. having a member 'arranged to rotate on the occurrence of a predetermined overload, a switch-closing member arranged toclose a switch when actuated a predetermined distance havi an engaging ortion adapted to connect said switch-closing member with the rotary portion of said motor to be actuated thereby, a switch adapted to close a circuit derived from the circuit to be controlled to actuate the motor, a single electromagnetically-operated device arranged to connect said switch-closing member with the rotary portion of said motor and close the switch which controls 65 the actuation-of the motor on the occurrence start the motor and also effect engagement.

of a predetermined overload on the circuit to be controlled and disconnect the same when the overload ceases.

14. In a time-limit controlling device for electric circuits, a rotary electric motor having Held coils through which current Hows from the circuit to be controlled and in proportion to the value thereof, and an armature having the circuit of its windings normally open, but adapted to be closed by a switch, a switch adapted to close the circuit of said armature windings to cause the motor to rotate on the occurrence of a predetermined overload on the main circuit, an actuating device 'adapted to close a switch controlling the main circuit, normally disengaged from the motor, and a means adapted to be moved by the magnetic effect of the Held on the occurrence of a predetermined load on the main circuit to cause said actuating-device to be connected with the rotary portion of said motor to be actuated thereby, to close the switch controlling the main circuit.

15. In a time-limit controlling device `for electric circuits, a rotary electric motor having vHeld coils through which current Hows from the circuit to be controlled and in proportion to the value thereof, and an armature having the circuit of its windin s normally open, but adapted to be close by a switch, a switch adapted to close the circuit of said armature windings to cause the motor to rotate on the occurrence of. a predetermined overload on the main circuit, an actu-- ating device adapted to close a switch controlling the main circuit, normally disengaged from the motor and a means adapted to be moved by the magnetic effect of the Held on the occurrence of a predetermined 105 load on the main circuit to cause said actuating-device to be connected with the rotary portion of said motor to be actuatedj thereby, to close the switch controlling the main circuit, and to close the controlling switch 110 for the circuit of the armature windings.

16. In a time-limit controlling device for electric circuits, a switch-closing member for the circuit to be controlled, havlng an engaging portion adapted to engage the rotary 115 portion of an electric motor, an electric motor having a rotary portion arranged to drive theswitch-closing member on engagement therewith, windings for the rotary portion of said motor, the circuit of which is 120 normally open at a switch, a switch ada ted to close the circuit of saidv windings, w ich windings are in inductive relation to the Held of the motor, Held coils through which ref'rect of the Held on the occurrence of a predetermined overload on the main circuit and cause the switch-closing mechanism to be connected with the rotary portion of said motor, to be actuated thereby, and also close the circuit of the windings of the armature, so that the motor will be caused to rotate.

17. A time-limit device for electric switches consisting of a switch operating device, an actuator therefor into and out of engagement with which said operating device is movable, an electric motor for driving said actuator, a controlling switch for said motor, and movable means for the movable member of said switch and said operating device, which means is responsive to a predetermined overload and upon occurrence of such overload moves said movable 15 member to close the controlling switch to start the motor and moves said operating device into engagement with its actuator.

ln testimony whereof, I have signed my name to this specification, in the presence of 20 two subscribing witnesses.

D. M. Smm, C. E. ENGLAND. 

